Removed include of ofxXmlSettings, no longer used
Config: num_stability_frames is unsigned.
Calibration: added bHasReceivedFirstFrame to mitigate ofxKinect crash. Not enabled as of now...
Calibration: bug fixes in main loop.

- corner_history now uses .resize instead of .reserve, and size is checked against config.num_stability_frames, not corner_history.size() or .capacity().
- projector chessboard corner coordinates are now in floats as per the new coordinate space [0,1]x[0,1].